An effective tsunami evacuation plan should take into consideration the cultural and social setting of the community exposed to the tsunami risk. In particular the plan should consider the level of tsunami risk perception by the population, the capacity of effective interactions among  the key players of a possible tsunami crisis and the population, and the impact of environmental, economical and social factors on the capacity of the population and key responders to properly react to a tsunami warning.

In order to properly understand the cultural and social background of the population of Setúbal in Portugal, which is built on a tsunami-prone area and was completely destroyed by an earthquake and tsunami in 1755, the EU funded SCHEMA project conducted an interesting questionnaire and interview based survey.

Mental maps were used for measuring awareness of space and of means of evacuation. During the questioning, the interviewees were presented with a map of Setúbal. They had to indicate their place of living and working, their view of the zone at tsunami risk, the safe places, and to choose a route for potential evacuation.

Most of the interviewees indicated a safe place as one far from the ocean and located at an elevated place, however very few of them indicated “easy to reach from where you are”,  “where you can group together” and “at a certain distance from buildings”. The survey reveals also the intention to use vehicles rather than to escape walking during the evacuation process. It might be explained by the localization of the safe zones and their height, but this choice can cause potential traffic jams and roads could be possibly obstructed  by collapsed buildings due to a previous earthquake.

The survey also showed that tsunami preparedness is refused by one third of the sample, either because they think that preparedness cannot be of any use in such a situation, or they think that a tsunami will not occur. Although more than half of the interviewees experienced an earthquake in December 2009 and was informed about the earthquake and tsunami of 1755, these factors appear to have had no positive influence on risk perception and awareness. Most of the people can quote the protective behaviours in case of earthquake, but only three persons applied them during quakes. It seems that knowledge is disconnected from behaviour; the image of an earthquake or a tsunami appears too abstract to be integrated into concrete behaviour.

Concerning the link between the 2009 earthquake and a potential tsunami, only people with specific knowledge or training made it immediately. Most of the times the link between an earthquake and a tsunami exists in theory; but, as in the Setúbal case, that link is not activated spontaneously by a real situation and is therefore insufficient to induce proper protective behaviour.

The survey provided the officers in charge of designing the tsunami evacuation plan for Setubal with a set of community specific factors that may facilitate or hamper the proper preparation of coastal communities for a tsunami.